Gains from a .63 turbine housing under 300 hp?

[Tim_K]

I'm working on assembling a T3 Garrett (stock T1 / T2 turbo) or my '89 2.5 Turbo Spirit. I've got ONE good paycheck coming, and I can either waste it all on bills, or buy something cool, like $200 or so in a .63 turbine housing or $300 in a custom calibration with 3 bar MAP sensor andd drop in my +40% injectors, or finish my ported head, which would be about $100-$300 depending on what I do and don't do to it.

I'd really like to put a .63 turbine housing on (with a 2.5" swingvalve either way, yes I know 3" is better, but unless YOU are going to pay for the parts......).

But I plan to build this 2.5 into the 250-275 WHP range, enough to move 3110 pounds at over 100 in the 1/4 mile. I need at least 250 WHP for that. Probably won't go much higher than that, at least not right now.

But I've read that the .48 housing can flow enough for 270 WHP, and I've seen the Daytona at thedodgegarage.com run to 310 WHP on the .48 . I'm wondering if the max HP numbers would be the same for both the 2.2 and 2.5 . I think they would be.

So my question here is, in the 250-275 WHP range, would I see any performance (1/4 mile time & ET) difference between a .48 and .63? I imagine the .48 would spool up a little quicker, but since I have a 2.5 and automatic transmission, I doubt there'd be much difference in that.

What do you think I should blow the cash on? .48, .63, custom cal & 3 bar, or bills?

[stampederunner]

I would get the custom cal. myself. It will allow you to safely go past 14 psi. Sure you can go past 14 psi with diode's and bleeds but that can be damaging if done wrong.

[Ondonti]

I think max hp #'s would be different, because they have different rpm's at which they are happy. This would lead me to believe that one is going to be making the turbo work harder at the same hp level.

If the 2.2 needs 22 psi to make 250fwhp and the 2.5 needs 23 psi (with the same turbo) to make that power or vice versa, you are going to see one take an efficiency drop before the other.
Thats just a made up example there. Both motors have a different peak rpm for HP when modified, and they probably are different in how hard they work the same turbo to make the same hp at their respective hp peaks.

[Ondonti]

The .48 housing probably needs as much help as possible making those big #'s while a .63 could get by with less. Now I personally would mix the best of those 2 situations........

[GLHNSLHT2]

go with the .63 on a 2.5 no matter what. Oh and it only takes 200hp to go 100MPH at that weight. Been there, done that at 12psi.

[OmniGuy123]

I would go for the cal and the +40s, as those will be the main limit in reaching your goals before the .48 housing will be. I would pull the turbo off when you get the cash for the housing and do it then.

[dodger]

Pay bills,get them out of the way,dont get cought in the TD bug.

[OmniGuy123]

Quote:

Originally Posted by dodger Pay bills,get them out of the way,dont get cought in the TD bug.

Thanks for being the voice of reason. I am not good at that at all.

[86Shelby]

I'm with dodger and cordes on this one. Without the bills hanging over your head you can get to the car stuff more freely.

[contraption22]

I agree with paying off the bills. Besides, you can easily reach your HP goals without upgrading your turbine housing.

[firebaron90]

Just get the cal. I ran a 13.6 on the stock turbo set up, and a good cal.


Joe

[Tim_K]

DAMN BILLS!!! No matter how many times I pay them, they always come back !!!

I can agree with most of the answers here. The .63 would be good, the custom cal would be good, the .48 would get me over 100 mph, and getting my ported head finished would be extra good. But once the ported head is on I'll probably NEED the custom cal to make it right on the fuel / air mixture.

I only need one more thing - money, or people who will give me the parts for free. Tough to come by either option!

I've had this set of +40's sitting around for a good 6 months now, might as well put them to use. And I would feel better about the computer being made to handle the extra boost and fuel without playing with diodes and 5th injectors and such things.

And I do worry about the custom computer or 3 bar MAP going bad, then I'm on the side of the road and don't have replacement parts, unless I put the stock computer and MAP in a box in the trunk and drag them with me everywhere I go and swap it all back if needed.

But I do have to get this tiny Mitsu turbo off the car and put the Garrett on, even if it's only a stock .48 rebuild.

Then I can spend money on shocks and struts, and the steering rack leaks a bit at the steering column seal, and the best way to change it is while the head and turbo are off for replacement..... See? The cash outlay never ends!